Update data/learning-tracks/README.md

Author: sarahs

data/learning-tracks/README.md

@@ -21,7 +21,7 @@ Learning track data for a product is defined in two places:
 
     For example, in `data/learning-tracks/actions.yml`, each of the items from the list in #1 is represented with additional data such as `title`, `description`, and a list of `guides` links.
 
-    One, and only one, learning track in this YAML must be designated as a "featured" learning track via `featured_track: true`, which will set it to appear at the top of the product sublanding page. Schema validation will fail if this property is missing.
+    One, and only one, learning track in this YAML must be designated as a "featured" learning track via `featured_track: true`, which will set it to appear at the top of the product sublanding page. A test will fail if this property is missing.
 
 Versioning for learning tracks is processed at page render time. The code lives in [`lib/learning-tracks.js`](lib/learning-tracks.js), which is called by `page.render()`. The processed learning tracks are then rendered by `layouts/product-sublanding.html`.